1. Field of the Invention
The present invention relates to a liquid ejection head, and a process for producing the same.
2. Description of the Related Art
A liquid ejection head which uses thermal energy and is used in an ink jet printing process and the like has a structure which uses a substrate formed from silicon or the like having a plurality of heat elements arranged thereon so as to form an array shape, and having a common heat storage layer or an electrical insulation layer provided thereon with respect to the plurality of the heat elements.
As is described in U.S. Pat. No. 6,273,557, for instance, the liquid ejection head having the above described structure includes: a fine ejection orifice for ejecting a droplet; a flow channel which communicates with the ejection orifice; and an ejection energy generating element provided in the flow channel, on a silicon substrate. A liquid supply port which communicates with the flow channel is formed in the silicon substrate.
Such a method of forming the liquid supply port of the liquid ejection head includes a method of subjecting the silicon substrate to two stages of etching treatments, as is described in U.S. Patent Application Publication No. 2009/0095708. In this method, a plurality of liquid supply ports are formed by subjecting a silicon substrate to a first etching which is crystal anisotropic etching, and subjecting the silicon substrate to a second etching which is dry etching.